Galvanized muffler with concavoconvex baffles



, June 3, 1952 F. c. BRIGHTLY, JR, ET AL 2,598,756

GALVANIZED MUFFLER WITH CONCAVO-CONVEX BAFFLES Filed 'Feb; 8, 1947 JTIL ETTTEFE FREDERICK C. BR/GHTLY JR. w JOHN F. HERBERT. b Z/zwymaw 5 Patented June 3, 1952 GALVANIZED MUFFLER WITH CONCAVO CONVEX BAFFLES" Frederick G'eBrightly, Jr., 1 Ghicago, and John F: Herbert, La, Grange, 111.

Application February 8, 1947, Serial No; 727,430

l Claim'. 1:

This invention relates to corrosion-resisting silencerssuch as exhaust mufflers-for internal combustion engines, and specifically the inven-- tion deals with a galvanized mufiierso constructed and arranged as to accommodate-easy drainageof molten zinc therefrom asthemufiler is removed from a zincbath.

Theinvention will hereinafter be specifically described as embodied in a muffler for the exhaustgases of an automobile internal combustion' engine, but'it should be understood that the principles of thi's'invention are generally applicable'to silencers and methods of makingrsame.

Automobile muiilers are conventionally made of inexpensive mild steel which quickly rusts. The rust particles soon clog the muiiier, thereby increasing the resistancezto gas flow andcdecreasing theefiiciency-of the-engine. In addition the rusted mufflersfrequently blow open, permitting the toxic. exhaust gases to enter the passenger space of the automobile with attendant ill effects zinc. The mufller construction of this invention is so arranged that the interior of the-.muffier is self draining to accommodate ready elimination of the. protective coatingmet'al beforeit becomes solidified in the interior of' the mufiier. Thus the. mufli'ers of "this invention have concave-convex end heads and baflles in place of heretofore-used flat end heads and tubes. These concave-convex units are centrally apertured'to be self draining when one end of the mufller is lower'than the other end. The body' of the muffler is preferabIy an inexpensively formed seam-welded mild steel tube; ly formed on identical stamping dies. The assembly is inexpensively made by spot-welding or the like. plied by dipping the welded-together assembly in a bath of molten metalsuch as' zinc, and excess metal is 1 drained fromthe assembly as it is lifted out of the molten bath with th'eapexes of the dished baiiles facing downwardly:

It is, then, an object of this invention to provide a galvanized-silencer for exahust gases and the like.

Another obj ectof this invention-is to'provid'ea mild'steel silencer composed of a tubular and concavo-convexend heads and' bafllesso arranged: that the body can: be immersed in galvanizing metal and excess metal readily drained The end heads and battles are inexpensive The protective metal coating is ap'--- therefrom before: itbecomes solidified in thein teri'or of the silencer:

A still further object of the invention" i to provide: an inexpensive method of rapidly" coating automobile mufflersv with a non-corrosive metal film.

A still further object of this invention is to provide. a process for galvanizing open-ended bafiled containers whereby all excess zinc. is re moved through gravity drainage.

A still further object of the invention iszto provide an automobile mufller havin a mild steelseam-welded tubular body, convex endheads welded in the ends of the-tubular body, and con cave-convex baflles traversing the interior of thebody at spaced intervals and being apertured so that complete gravity drainage out of one end" of the body is facilitated.

Other and further objects of theinvention will be'apparent to those skilled in the art. from the following detaileddescription of the annexed sheet of drawings which ,by way of a preferred ess of hot dipgalvanizing automobile muiilers in accordancewith this invention.

Figure 2 is a longitudinal cross-sectional view of an automobile mufil'er according to-this invention;

Figure 3 -is a cross-sectional view taken along-- 7 the III-II-I of'Figure 1 and illustrating the man-- nor in which the mufiiers of thi invention are supported in a feeder chute, during the hot dip:

galvanizinglprocess.

Figure 4 is; a transverse cross-sectional view taken along the line IVIV of Figure 2.

As shown on the drawings:

Muffiers Id of this invention are galvanized as illustrated Figure 1 by first immersing the. same: in a pickling tank ll' containing an-ac-i'd bathiZ such as a 107% solutionof sulphurica'cid; a hydrochloric acid solution, or the like-e The monium' chloride flux. solution (notshown) with the bafiles in the same positions as shown in the pickling'tankwof Figure. 1- Next the fluxed mufiflers are fed intothe upper end of: a chute It4- which slopes downwardly into a tank IS. The tank l5 contains a bath l6 of molten zinc. The zinc is kept in a heated condition by heat from a combustion chamber l! surrounding the tank. Gas or oil-fed nozzle l8 extend into the combustion chamber to heat the tank. A baffle l9 extends across the tank above the chute l4 and dams off a pond of flux floating on top of the molten zinc [6 so that the mufilers H] in the chute l4 must first pass through the flux bath before reaching the zinc bath.

The chute l4, as best shown in Figure 3, is composed of a pair of bottom angle strips Ma and a pair of top angle strips [4b. The strips are welded to straps l4c which hold them apart to define a central passageway sized for receiving the mufflers Ill. The mufflers ride on the end edges only of the inwardly projecting legs of the strips. The lower end of the chute, as shown in Figure 1, is substantially horizontal and the bottom strips I la project beyond the top strips, so that, as a muffler emerges from under the top strips [4b it is free to float upwardly in the bath I6 as illustrated in dotted lines. A hook 21 is provided for lifting the mufiler in out of the bath As best shown in Figure 2, the muffler i0 is composed of a tubular body 22, end heads 23 carrying nipples 24, and bafiies at spaced intervals in the tube between the end heads. The tubular body 22 is composed of mild steel and is held in tubular form by a seam weld 22a. The end heads 23 are in the form of circular disks with cylindrical flanges or collars 23a around the periphery thereof snugly fitting in the ends of the tube and welded thereto as by spot welds 26. These disks have concavo-convex main body portions 23b and are positioned so that the convex sides face the outside of the tube. The apexes of the body portions 23b are centrally apertured to provide relatively large holes 230 therethrough. The nipples 24 have tubular main body portions 24a snugly fitting through the holes 230 together with outturned flange portions 241) underlying the concave faces of the main body portions 23b around the holes 230 and secured thereto as by a welded bond 21.

The baflies 25 are of the same identical shape and size as the end heads 23 and have cylindrical flanges or collars 25a snugly fitting inside the tube 22 together with concave-convex main body portions 25b. These body portions 25b, as well as the body portions 23b, extend inwardly of the surrounding flanges or collars, but preferably do not project beyond the flanges or collars.

Each baffle has a central aperture 250 at the apex of the body portion 251). This aperture is surrounded by a plurality of larger diameter holes 25d, four such holes being shown in Figure 4. The collars or flanges 25a of the baffles are welded to the tube 22 as by spot welds 28.

It will be noted from Figure 2 that the concavo-convex main bodies 251) of the baffles 25 all extend in the same direction so that the holes 25c therein will accommodate gravity drainage to the left-hand end head 23 whenever the baffle is inclined to lower this end. Conversely, these holes 250 will be uppermost whenever the muffler is inclined in the other direction. This feature is important in the process of galvanizing the mufilers as is shown in Figure 1.

When the muffler I0 is immersed in the pickling bath l2, the holes 250 of the baffles are uppermost so that hydrogen gas eliminated during the pickling operation can readily rise out of the top end of the muffler, thereby eliminating heretofore-encountered gas pockets when pickling hollow articles. The escape of the gas insures complete filling of the interior of the muflier with the pickling liquid so that all parts of the muffler will be cleaned. To remove the muflier from the pickling bath it is merely lifted by the hook 13 which is inserted through the top nipple 24 and engaged against the body 23b of the end head.

The pickled muffler, after being rinsed in water and fluxed in zinc ammonium chloride, is then shoved into the upper end of the chute I4 with the holes 250 in the baffles still in an uppermost position. The nipple 24 on the leading end of one muflier engages the nipple 24 on the trailing end of the previous muiller, and, as each mufller is forced into the upper end of the chute l4, filled with the mufflers, the mufliers are advanced down through the fiux bath into the zinc bath and out of the bottom end of the chute. As they are thus advanced, all surfaces, both interior and exterior, are first coated with flux material such as salts like zinc chloride, and are then coated with zinc. The zinc flows through the entire muffler as well as around the muffler, since the angle strips of the chute only have line contact on the body 22 of the muffler. Thus zinc flows through the nipple at 24 on the leading end of the muffler into the interior of the tube 22 and then flows through the apertures in the baflles 25 and finally out of the nipple in the trailing end of the muffler. This flow is not trapped by air in the mufller since the air will rise out of the nipple at the trailing end of the muffler.

As a result of this treatment in the zinc bath, a complete zinc coating 29 is deposited on all surfaces, both interior and exterior, of the tubular body 22, the end heads 23, the nipples 24, and the baffles 25. The zinc films will form fillets 29a sealing off any welded areas in metal to metal contact.

When the muffler emerges from under the top strips Mb of the chute, it will float to the top of the zinc bath l6 whereupon the leading nipple 24 receives a hook 2| therein to raise the zinccoated muflier above the bath 16. The muffler will then assume the vertical position shown in Figure 1 with the apexes of the baffles assuming the lowermost position so that the holes 250 will drain out all excess molten zinc for fiow through the bottom nipple. As a result, no excess zinc beyond that necessary for the coating 29 is retained in the muffler.

The zinc bath is preferably maintained at temperatures around 850 F. so that the zinc will remain sufficiently molten when it is raised above the bath to permit drainage of excess zinc. The galvanized muffler, although completely coated on all surfaces, is free from zinc pellets or slugs which are conventionally trapped in hollow articles that do not have the self-draining feature of the muffler of this invention.

From the above descriptions it will be understood, therefore, that this invention provides an all-welded silencer composed of the same type of inexpensive mild steel heretofore used, but coated with a corrosion-resistant material such as zinc and having apertured self-draining baffles replacing the heretofore-necessary muffler tubes. The silencer is free from heretofore-used lock-seams which might unlock or rupture from expansion due to the heat conditions incidental to galvanizing. It will also be understood that the end heads and baffles of the mufller of this invention can be made on the same stamping equipment, since they are identically shaped.

It will be further understood that the mufflers of this invention automatically release gases through one open end thereof, and automatically drain excess coating material through this same open end without the possibility of trapping any of the gases or liquids.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claim.

We claim as our invention:

A muflier of simplified design adapted to be uniformly and completely coated by means of a galvanizing process carried out at the completion of fabrication and assembly thereof, comprising a metal tube, a plurality of identically dished metal disks each having a peripheral collar sized for snugly fitting said tube and a uniformly curved concavo-convex segmental spherical main body extending from the collar to a central apertured apex, two of said disks having enlarged central apertures and flanged nipples extending through the apertures thereof with the flanges bottomed on and welded to the concave faces around the apertures, said two disks having the collars thereof seated in and welded to opposite ends of the tube to form end heads for the tube with the concave faces of the disks inside the tube and the nipples extending outwardly from the ends of the tube, the other of said disks being disposed in the tube at spaced intervals between said end heads 6 and having the collars thereof welded to the tube, said other of said disks having additional relatively larger gasflow apertures surrounding the smaller central drainage aperture thereof and all of the thus apertured main bodies having their apexes extending in the same direction whereby gravity drainage through the tube is insured when the axis of said tube is displaced from the horizontal, and a zinc coating on all exposed surfaces of the tube, the disks, and the nipples.

FREDERICK C. BRIGHTLY, JR. JOHN F. HERBERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 689,797 Erwin Dec. 24, 1901 1,081,340 Unke et a1 Dec, 16, 1913 1,155,317 Mark Sept. 28, 1915 1,756,916 Stranahan Apr. 29, 1930 1,810,252 Noonan June 16, 1931 1,867,273 Lemmerman July 12, 1932 1,990,837 Morgenstern Feb. 12, 1935 2,150,768 Hedrick Mar. 14, 1939 2,345,058 Matteson Mar. 28, 1944 2,348,696 Schabacker May 9, 1944 2,365,846 Seaborne Dec. 26', 1944 2,373,038 Lindsay Apr. 3, 1945 2,416,452 Marx Feb. 25, 1947 FOREIGN PATENTS Number Country Date 364,222 Great Britain Jan. 7, 1932 

